I think drexplode has a major fault in his statement, and obviously he does not drive on the track.
There are a lot of cars on the track days. From Toyota Corolla to Ferrari F430, not to mention all the Alfa Romeos.
If you tell me doing 20 or so laps in 5 hot lap lots for 3 times and you have caliper problem???
My cheaper Mazda RX-8 had 10 similar track days and worn out 3 pads and a brake disc. Still looks like it is new when I swapped it for AP Racing caliper for more braking power.
Tell me Mazda RX-8 is more "track ready" then a BMW 135i